Muffler with plural passages



Jan. 6, 1953 R. B. BOURNE 2,624,418

I MUFFLER WITH PLURAL PASSAGES Filed Aug. 1, 1951 Roland B. Bourne Inventor Patented Jan. 6, 1953 MUFFLER WITH PLURAL PAS SAGES Roland B. Bourne, West Hartford, 001111., asslgnor to The Maxim Silencer Company, Hartford, Conn., a corporation of Connecticut Application August 1, 1951, Serial No. 239,674

2 Claims.

This invention relates to silencing devicesfor internal combustion engines, and in particular to silencers which are mounted in confined spaces: which require holding the diameter of the shellof the silencer to a minimum. One object is to produce a silencer which comprises an expansion: chamber into and out of which the exhaust gas capable of withstanding high external hydraulic pressure and so constructed as to reduce greatly the transmission of sound from the silencerto the surrounding water.

The invention will now be described with ref: erence to the accompanying drawing, in which Fig. l is a median section through the silencer, taken on line l-I of Figs. 2 to 6 inclusive;

Fig. 2 is a section on line 2-2 of Fig. 1;

Fig. 3 is a section on line 33 of Fig. 1;

Fig. 4 is a section on line 4-4 of Fig. 1;

Fig. 5 is a section on line 55 of Fig. 1; and

Fig. 6 is a section on line 66 of Fig. 1'.

The silencer is enclosed primarily in a cylindrical pressure shell l0, preferably of circular cross-section and formed of stainless steel about one inch thick so that it will withstand a pressure of 700. p. s. i. g. Within the pressure shell are cylindrical laminations of sheet metal H and I2, here shown as two in number, but which may be varied in number in different chambers of the silencer if desired. These laminations are not relied on so much for strength as for deadening sound transmission through the outer shell, and in combination with a pressure shell which is relatively massive prove remarkably and unexpectedly eflicient in that regard. An inlet conduit l3 passes through one end of the pressure shell into 'a chamber l4 defined by the shell and an intermediate transverse partition I5. The inlet conduit terminates with an open end at approximately the midpoint of the chamber H. An outlet conduit |6 enters the other end of the pressure shell and terminates with an open end within and about halfway along a chamber l1 defined by the pressure shell and a second intermediate transverse partition 18. The inlet and outlet conduits preferably have antiresonance slots l9 and respectively.

A plurality of intermediate tubes 2|, preferably 2 having their entrance ends flared as at 22, are circumferentially spaced as best shown in Fig. 3 and extend from a point in chamber l4 adjacent the terminus of the inlet conduit through the partition l5 and open into the chamber 23 formed between partitions I5 and IS. A second circular series of tubes 24 pass through the partition I8, and have open ends in both chamber 23 and chamber ll, terminating in the latter adjacent the entrance end of the outlet conduit. The entrance ends of the tubes 24 are preferably flared at 25 and that of the outlet conduit flared at 26.

It will be noted that the series of tubes 2| are located radially outwardly of the inlet conduit so that there can be no direct gas or sound passage from one to the other, and that a similar relationship exists between tubes 24 and the outlet conduit IB. Tubes 2| and tubes 24 are both arranged in sets adjacent the shell of the silencer, and in order to prevent direct transmission the ends of tubes 2! are bent inwardly towards the center of the chamber 23 as is shown in Figs. 1 and 4. The two sets of tubes 2| and 24 are preferably provided with anti-resonance holes 27 as described in my Patent 2,297,046, September 29, 1942.

What I claim is:

l. A silencer having a substantially cylindrical shell, a pair of spaced partitions dividing the interior of the shell into three chambers, an inlet conduit leading into the first chamber and terminating with an open end near the center thereof, a circumferentially spaced series of tubes located radially outwardly of the inlet conduit each having open ends one substantially in the plane of the open end of the inlet conduit and the other near the center of the second chamber, said tubes passing through the first partition into the second chamber and slanting radially inwardly towards the axis thereof, a second circumferentially spaced series of tubes circumferentially staggered with relation to the tubes of the first series, said second series of tubes extending substantially straight through the second partition into the second and third chambers and having open ends at substantially the mid-points of said chambers, and an outlet conduit entering the third chamber through the shell and terminating with an open end substantially in the plane of the open ends of the second series of tubes but located radially inwardly thereof.

2. A silencer having a substantially cylindrical shell, a. pair of transverse partitions dividing the interior of the shell into three chambers, a pair of conduits coaxial with the shell and entering each end chamber respectively with an open end REFERENCES CITED at a point intermediate its length two series of The following references are of record in the circumferentially spaced tubes located adjacent file of this patent: the peripheries of said end chambers and sta gered circumferentially with respect to each other, 5 UNITED STATES PATENTS the tubes in each series terminating at substan- Number Name Date tially the midpoint of the middle chamber with 2,265,342 Bourne Dec. 9, 941

open ends, the tubes of one series being bent i inwardly at one end to open into the middle FOREIGNPATENTS chamber closer to the axis of the cylindrical shell 10 Number Country a than the tubes in the other series. 139,369 at Britain Mar- 4. 1920 882,317 France May 31, 194 3 ROLAND'B. BOURNE'. 1 24rz55- Australia Jan. 27,194 

